In recent years, the performance of an electronic device such as a computer or the like is rapidly improving and the function of it is being rapidly enhanced. With the improvement and enhancement of the electronic device, an amount of heat generated by an integrated circuit or the like used in the electronic device increases.
In such electronic device, a technology in which a cooling device dissipates heat generated by a heat generating element such as an integrated circuit or the like by using a phase change cooling system is known (for example, patent literatures 1 to 5). Further, in the cooling device using the phase change cooling system, a principle in which vapor accumulates in a vertically upper part is used and a thermal siphon-type cooling structure in which a heat receiving unit is provided in the lower part of the cooling device and a heat dissipating unit is provided in the upper part of the cooling device is adopted. By using this structure, a pump for circulating refrigerant is not required for the cooling device using the phase change cooling system.
In patent literature 1, a technology in which in an ebullient cooling device, the heat receiving unit and the heat dissipating unit are integrally formed and whereby, interference between a component around a heat generating body and a cooling tank can be prevented is disclosed.
In patent literature 2, a technology in which in the cooling device using a siphon effect, a condenser is disposed above a vaporizer in the vertical direction and whereby the power consumption and noise of the cooling device can be reduced is disclosed.
In patent literature 3, a technology in which in a pumpless cooling system, a heat radiator is disposed above a heat exchanger in the vertical direction (like the technology disclosed in patent literature 2) and one pipe is used for conveying refrigerant and whereby high reliability and low thermal resistance are realized is disclosed.
In patent literature 4, a technology in which in an ebullient cooler, a pipe having a two-layer structure through which refrigerant flows is used and whereby a liquid-phase flow path and a vapor-phase flow path are separated from each other and a high heat dissipation performance can be obtained is disclosed.
In patent literature 5, a technology of a cooling system and an electronic device in which in a cooling system which cools a plurality of heat generating elements, a plurality of heat dissipating units are disposed in line in a direction parallel to a width direction (a horizontally lateral direction) of a chassis of the electronic device and whereby a cool wind for cooling can be supplied to each of a plurality of the heat dissipating units is disclosed.